131312221 has 8 divisors (see below), whose sum is σ = 138380544. Its totient is φ = 124357200.

The previous prime is 131312213. The next prime is 131312227. The reversal of 131312221 is 122213131.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 131312221 - 2³ = 131312213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 131312195 and 131312204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131312227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25941 + ... + 30586.

It is an arithmetic number, because the mean of its divisors is an integer number (17297568).

Almost surely, 2^131312221 is an apocalyptic number.

It is an amenable number.

131312221 is a deficient number, since it is larger than the sum of its proper divisors (7068323).

131312221 is a wasteful number, since it uses less digits than its factorization.

131312221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56651.

The product of its digits is 72, while the sum is 16.

The square root of 131312221 is about 11459.1544626992. The cubic root of 131312221 is about 508.2784720035.

Adding to 131312221 its reverse (122213131), we get a palindrome (253525352).

The spelling of 131312221 in words is "one hundred thirty-one million, three hundred twelve thousand, two hundred twenty-one".